Solar photovoltaic silicone thermal pads

Photovoltaic inverter heat dissipation becomes a problem? Changmai silicone Thermal Pad and thermal insulation sheet can easily solve this problem!

In the rapidly developing photovoltaic industry, silicone, as a key material, is widely used in the fields of solar panel encapsulation, junction box sealing, component frame sealing, and photovoltaic inverter potting due to its excellent weather resistance, insulation, high light transmittance and good bonding performance. With the popularization of clean energy, photovoltaic inverters are also key equipment for converting direct current generated by solar panels into alternating current for home and industrial use. Their stability and heat dissipation performance are crucial. In this regard, thermal conductive silicone pad play an indispensable role.

Photovoltaic inverters generate a lot of heat during operation. If the heat dissipation is poor, it will affect the performance and life of the equipment. Traditional heat dissipation methods such as natural cooling or fan cooling no longer meet the needs in some high-performance inverters. At this time, thermally conductive silicone sheets, as an efficient thermal interface material, are widely used to improve the heat dissipation efficiency of inverters.

This article will give a detailed introduction to the basic properties, preparation process, classification, performance testing and application of photovoltaic silicone in the photovoltaic field.

一、Silicone thermal pad

The main function of the solar panel in the photovoltaic inverter is to fill the tiny gap between the components and the heat sink, effectively transferring the heat generated by the components to the heat sink, thereby maintaining the stability of the internal temperature of the inverter. Its advantages are mainly reflected in the following aspects：

1.Excellent weather resistance: It can maintain stable performance under extreme weather conditions (such as high temperature, low temperature, ultraviolet radiation), ensuring the long-term service life of photovoltaic modules.

2.Good insulation: high resistivity, effectively preventing current leakage and protecting circuit safety.

3.High light transmittance: for light-transmitting silicone, its light transmittance is excellent and does not affect the photoelectric conversion efficiency of photovoltaic panels.

4.Excellent adhesion: can achieve good adhesion with a variety of materials (such as glass, metal, plastic, etc.), ensuring the sealing and structural strength of photovoltaic modules.

5.Low toxicity and environmental friendliness: Some photovoltaic silicones use environmentally friendly curing agents, which are non-toxic and harmless, and meet the development requirements of green energy.

Preparation process of photovoltaic silica gel

1.Raw material preparation: Using high-purity silicon powder, methyl chloride, etc. as raw materials, a series of chemical reactions are performed to generate methylchlorosilane monomer.

2.Hydrolysis polymerization: Methylchlorosilane monomer is hydrolyzed to form polydimethylsiloxane (PDMS) under the action of a hydrolysis catalyst.

3.Modification treatment: According to the specific needs of photovoltaic applications, PDMS is modified, such as adding fillers, curing agents, coupling agents, etc., to enhance the specific properties of silicone.

4.Mixing molding: Mix the modified silicone raw materials evenly in a certain proportion and make them into the desired shape by extrusion, molding or infusion.

5.Curing and cross-linking: Under certain conditions (such as temperature, humidity, and catalyst), silicone undergoes a cross-linking reaction to form a three-dimensional network structure, completing the curing process.

Classification of photovoltaic silicone

Photovoltaic silicone can be divided into many types according to different curing methods, cross-linking types and application scenarios:

1.According to the curing method: single-component silicone (such as dealcohol type, deketoxime type) and two-component silicone (A and B glues need to be mixed in proportion).

2.According to the cross-linking type, it can be divided into condensation type silicone (RTV) and addition type silicone (LTV). Condensation type silicone will release small molecules (such as alcohol, ketone oxime, etc.) during the curing process, while addition type silicone will not, so addition type silicone is more suitable for occasions with high requirements for cleanliness.

3.According to thermal conductivity:

For the same thermal conductive material, thermal conductivity is a characteristic of the material itself, it is a fixed value, and the thermal resistance value will change with the change of thickness.

Similarly, the thicker the thermal conductive material, the farther the heat transfer through the material, the longer the time, and the worse the thermal conductivity.

For thermal conductive silicone sheets, choosing the right thermal conductivity and thickness has a lot to do with its thermal conductivity. Choose a silicone sheet with high thermal conductivity, but the thickness is large, but the performance is not good enough. When choosing thermal conductive silicone sheets, the ideal situation is: high thermal conductivity, ideal thickness and contact pressure to ensure the best interface contact.

All the heat of the thermal conductive silicone sheet is conducted from one end to the other through the material, and it is almost impossible to achieve such conditions. The thermal resistance value obtained by testing and calculation is actually the thermal resistance value of the thermal conductive material + the thermal resistance value of the contact surface. Due to the different contact surface environments, the thermal resistance values ​​measured under different conditions for the same material are also different.

Application value of silicone thermal pads

In today's era of rapid technological development, thermal conductive silicone and silicone rubber have shown broad application prospects in many fields, especially in the fields of new energy vehicles and electronic equipment, due to their excellent thermal conductivity and stability. Applicable fields:

1. Power semiconductor components
2. Engine control module
3. Automotive electronic products
4. Power supply products
5. LED production plant

Used for large-area flat heat dissipation such as power supplies. Thermal conductive gaskets have low costs, are non-drying, and are easy to replace. Their thermal conductivity is generally low, 1.0~4W/m.K. In electronic products, they are generally used for some electronic parts and chip surfaces that have low heat generation but are not easy to dissipate heat. At the same time, sticking to the heat dissipation interface can also play an additional role of buffering and stabilization. This material not only plays an important role in the high-voltage lines in new energy vehicles, but is also an indispensable component in equipment such as induction cookers, PCB board radiators and photovoltaic inverters.